The present invention relates to a torsional vibration damper assembly for use in a torsion coupling between a pair of axially aligned shafts, in a clutch for a manual transmission or in a lock-up clutch for a torque converter of an automatic transmission.
Vibration in a vehicle drive train has been a long-standing problem due to the sudden shock of engagement of the clutch disc in a vehicle clutch for a manual transmission and to the torque fluctuations occurring in an internal combustion engine. The use of a vibration damper has been long accepted as a way of counteracting these torsional vibrations from the vehicle engine which would otherwise cause undesirable characteristics, e.g., impact loads, pulsations, noises, etc., in the transmission and driveline during operation of the vehicle.
In an automatic transmission having a constant slipping device, torsional vibrations are not a problem unless a lock-up clutch is utilized to provide direct drive in order to enhance fuel economy. Without the lock-up clutch, the vibrations are absorbed hydraulically; but when the torque converter is locked in direct drive, a vibration damper is required to eliminate any disturbance resulting from torsional vibration. Likewise, the vibration damper assembly is convenient for use as a flexible coupling between an input shaft and output shaft where flexibility is required. The present invention provides a novel vibration damper assembly that will be useful in all of these various applications.
The present invention comprehends a novel vibration damper assembly which provides a relatively low rate, high amplitude deflection between the torque input and output elements. The assembly includes mounting means operatively connected to a torque input, drive members on the mounting means, a hub barrel and drive plates or arms connected together and operatively connected to the output, a plurality of floating spacers, and resilient spring means positioned in the path of the drive members, floating spacers and drive plates to provide a resilient connection between the mounting means and the hub.
The present invention also comprehends a novel vibration damper assembly providing an extended arc of deflection between the driving and driven members. The hub is secured to a dish-shaped cover plate which has a generally flat base and an annular depending flange or side. The interior surface of the flange provides a guiding surface for the floating spacers each of which contains a roller contacting the guiding surface. The resilient springs contact converging sides of the wedge-shaped spacers.
The present invention further comprehends a novel vibration damper assembly wherein the resilient springs are arranged into two groups acting in parallel, with each group comprising several spring sets of concentric springs acting in series.
The present invention also comprehends the provision of a novel vibration damper wherein the floating spacers have a narrow circumferentially extending outer flange or base received in a guide channel formed in the damper housing; the spacer having wings or tabs formed at the ends of the flange to contact the channel under the radially outward component of the spring force and centrifugal force to provide a controlled lag in the operation of the damper.
Further objects of the present invention are to provide a construction of maximum simplicity, efficiency, economy and ease of assembly and operation, and such further objects, advantages and capabilities as will later more fully appear and are inherently possessed thereby.